Method and apparatus for handling BWP switching in random access procedure

ABSTRACT

A method for random access performed by a MAC entity of a UE is provided. The method includes: receiving a first beam failure recovery configuration of a first UL BWP; receiving a second beam failure recovery configuration of a second UL BWP; initiating a first RA procedure on the first UL BWP by applying at least one first RA parameter configured in the first beam failure recovery configuration, when a number of beam failure instances that have been received from lower layers is larger than or equal to a threshold; switching an active UL BWP of the UE from the first UL BWP to a second UL BWP before completion of the first RA procedure; and initiating a second RA procedure on the second UL BWP by applying at least one second RA parameter configured in the second beam failure recovery configuration, after switching to the second UL BWP.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims the benefit of and priority to aprovisional U.S. Patent Application Ser. No. 62/754,136, filed on Nov.1, 2018, entitled “Method of BWP Switching within Random AccessProcedure,” (hereinafter referred to as “US75367 application”). Thedisclosure of the US75367 application is hereby incorporated fully byreference into the present application.

FIELD

The present disclosure generally relates to wireless communication, andmore particularly, to a Random Access (RA) procedure in the nextgeneration wireless communication networks.

BACKGROUND

Various efforts have been made to improve different aspects of wirelesscommunications, such as data rate, latency, reliability and mobility,for the next generation (e.g., fifth generation (5G) New Radio (NR))wireless communication systems. In NR, an RA procedure may includeactions, such as an RA procedure initialization, an RA resourceselection, an RA preamble transmission, an RA response reception, and acontention resolution. In addition, in NR, a serving cell may beconfigured with one or multiple bandwidth parts (BWPs). During anongoing RA procedure, a user equipment (UE) may switch its active BWPfrom one to another. Thus, there is a need in the industry for animproved and efficient mechanism for a UE to handle BWP switching duringan ongoing RA procedure.

SUMMARY

The present disclosure is directed to a method for random accessperformed by a UE in the next generation wireless communicationnetworks.

According to an aspect of the present disclosure, a UE is provided. TheUE includes one or more non-transitory computer-readable media havingcomputer-executable instructions embodied thereon and at least oneprocessor coupled to the one or more non-transitory computer-readablemedia. The at least one processor is configured to execute thecomputer-executable instructions to: receive, by a Medium Access Control(MAC) entity of the UE, a first beam failure recovery configuration of afirst uplink (UL) BWP; receive, by the MAC entity of the UE, a secondbeam failure recovery configuration of a second UL BWP; initiate, by theMAC entity of the UE, a first RA procedure on the first UL BWP byapplying at least one first RA parameter configured in the first beamfailure recovery configuration of the first UL BWP, when a number ofbeam failure instances that have been received from lower layers of theUE is larger than or equal to a threshold; switch, by the MAC entity ofthe UE, an active UL BWP of the UE from the first UL BWP to a second ULBWP before completion of the first RA procedure; and initiate, by theMAC entity of the UE, a second RA procedure on the second UL BWP byapplying at least one second RA parameter configured in the second beamfailure recovery configuration of the second UL BWP, after switching theactive UL BWP of the UE to the second UL BWP.

According to another aspect of the present disclosure, a method forrandom access performed by a MAC entity of a UE is provided. The methodincludes: receiving a first beam failure recovery configuration of afirst UL BWP; receiving a second beam failure recovery configuration ofa second UL BWP; initiating a first RA procedure on the first UL BWP byapplying at least one first RA parameter configured in the first beamfailure recovery configuration of the first UL BWP, when a number ofbeam failure instances that have been received from lower layers of theUE is larger than or equal to a threshold; switching an active UL BWP ofthe UE from the first UL BWP to a second UL BWP before completion of thefirst RA procedure; and initiating a second RA procedure on the secondUL BWP by applying at least one second RA parameter configured in thesecond beam failure recovery configuration of the second UL BWP, afterswitching the active UL BWP of the UE to the second UL BWP.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the example disclosure are best understood from the followingdetailed description when read with the accompanying figures. Variousfeatures are not drawn to scale. Dimensions of various features may bearbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a diagram illustrating an example contention-based RA (CBRA)procedure, according to an example implementation of the presentapplication.

FIG. 2 is a diagram illustrating an example contention-free RA (CFRA)procedure, according to an example implementation of the presentapplication.

FIG. 3 is a flowchart of an example method performed by a MAC entity ofa UE in an RA procedure, according to an example implementation of thepresent application.

FIG. 4A is a flowchart of another example method performed by a MACentity of a UE in an RA procedure, according to an exampleimplementation of the present application.

FIG. 4B is a flowchart of another example method performed by a MACentity of a UE in an RA procedure, according to an exampleimplementation of the present application.

FIG. 5 is a block diagram illustrating a node for wirelesscommunication, according to various aspects of the present application.

DETAILED DESCRIPTION

The following description contains specific information pertaining toexample implementations in the present disclosure. The drawings in thepresent disclosure and their accompanying detailed description aredirected to merely example implementations. However, the presentdisclosure is not limited to merely these example implementations. Othervariations and implementations of the present disclosure will occur tothose skilled in the art. Unless noted otherwise, like or correspondingelements among the figures may be indicated by like or correspondingreference numerals. Moreover, the drawings and illustrations in thepresent disclosure are generally not to scale, and are not intended tocorrespond to actual relative dimensions.

For the purpose of consistency and ease of understanding, like featuresmay be identified (although, in some examples, not shown) by the samenumerals in the example figures. However, the features in differentimplementations may be differed in other respects, and thus shall not benarrowly confined to what is shown in the figures.

The description uses the phrases “in one implementation,” or “in someimplementations,” which may each refer to one or more of the same ordifferent implementations. The term “coupled” is defined as connected,whether directly or indirectly through intervening components, and isnot necessarily limited to physical connections. The term “comprising,”when utilized, means “including, but not necessarily limited to”; itspecifically indicates open-ended inclusion or membership in theso-described combination, group, series and the equivalent. Theexpression “at least one of A, B and C” or “at least one of thefollowing: A, B and C” means “only A, or only B, or only C, or anycombination of A, B and C.”

Additionally, for the purposes of explanation and non-limitation,specific details, such as functional entities, techniques, protocols,standard, and the like are set forth for providing an understanding ofthe described technology. In other examples, detailed description ofwell-known methods, technologies, systems, architectures, and the likeare omitted so as not to obscure the description with unnecessarydetails.

Persons skilled in the art will immediately recognize that any networkfunction(s) or algorithm(s) described in the present disclosure may beimplemented by hardware, software or a combination of software andhardware. Described functions may correspond to modules which may besoftware, hardware, firmware, or any combination thereof. The softwareimplementation may comprise computer executable instructions stored oncomputer readable medium such as memory or other type of storagedevices. For example, one or more microprocessors or general-purposecomputers with communication processing capability may be programmedwith corresponding executable instructions and carry out the describednetwork function(s) or algorithm(s). The microprocessors orgeneral-purpose computers may be formed of Applications SpecificIntegrated Circuitry (ASIC), programmable logic arrays, and/or using oneor more Digital Signal Processor (DSPs). Although some of the exampleimplementations described in this specification are oriented to softwareinstalled and executing on computer hardware, nevertheless, alternativeexample implementations implemented as firmware or as hardware orcombination of hardware and software are well within the scope of thepresent disclosure.

The computer readable medium includes but is not limited to RandomAccess Memory (RAM), Read Only Memory (ROM), Erasable ProgrammableRead-Only Memory (EPROM), Electrically Erasable Programmable Read-OnlyMemory (EEPROM), flash memory, Compact Disc Read-Only Memory (CD-ROM),magnetic cassettes, magnetic tape, magnetic disk storage, or any otherequivalent medium capable of storing computer-readable instructions.

A radio communication network architecture (e.g., a Long Term Evolution(LTE) system, an LTE-Advanced (LTE-A) system, an LTE-Advanced Prosystem, or a 5G NR Radio Access Network (RAN)) typically includes atleast one base station, at least one UE, and one or more optionalnetwork elements that provide connection towards a network. The UEcommunicates with the network (e.g., a Core Network (CN), an EvolvedPacket Core (EPC) network, an Evolved Universal Terrestrial Radio Accessnetwork (E-UTRAN), a 5G Core (5GC), or an internet), through a RANestablished by one or more base stations.

It should be noted that, in the present application, a UE may include,but is not limited to, a mobile station, a mobile terminal or device, auser communication radio terminal. For example, a UE may be a portableradio equipment, which includes, but is not limited to, a mobile phone,a tablet, a wearable device, a sensor, a vehicle, or a Personal DigitalAssistant (PDA) with wireless communication capability. The UE isconfigured to receive and transmit signals over an air interface to oneor more cells in a radio access network.

A base station may be configured to provide communication servicesaccording to at least one of the following Radio Access Technologies(RATs): Worldwide Interoperability for Microwave Access (WiMAX), GlobalSystem for Mobile communications (GSM, often referred to as 2G), GSMEnhanced Data rates for GSM Evolution (EDGE) Radio Access Network(GERAN), General Packet Radio Service (GPRS), Universal MobileTelecommunication System (UMTS, often referred to as 3G) based on basicwideband-code division multiple access (W-CDMA), high-speed packetaccess (HSPA), LTE, LTE-A, eLTE (evolved LTE, e.g., LTE connected to5GC), NR (often referred to as 5G), and/or LTE-A Pro. However, the scopeof the present application should not be limited to the above-mentionedprotocols.

A base station may include, but is not limited to, a node B (NB) as inthe UMTS, an evolved node B (eNB) as in the LTE or LTE-A, a radionetwork controller (RNC) as in the UMTS, a base station controller (BSC)as in the GSM/GERAN, a ng-eNB as in an E-UTRA base station in connectionwith the 5GC, a next generation Node B (gNB) as in the 5G-RAN, and anyother apparatus capable of controlling radio communication and managingradio resources within a cell. The base station may serve one or moreUEs through a radio interface.

The base station is operable to provide radio coverage to a specificgeographical area using a plurality of cells forming the radio accessnetwork. The base station supports the operations of the cells. Eachcell is operable to provide services to at least one UE within its radiocoverage. More specifically, each cell (often referred to as a servingcell) provides services to serve one or more UEs within its radiocoverage (e.g., each cell schedules the downlink and optionally uplinkresources to at least one UE within its radio coverage for downlink andoptionally uplink packet transmissions). The base station cancommunicate with one or more UEs in the radio communication systemthrough the plurality of cells. A cell may allocate sidelink (SL)resources for supporting Proximity Service (ProSe) or Vehicle toEverything (V2X) service. Each cell may have overlapped coverage areaswith other cells.

As discussed above, the frame structure for NR is to support flexibleconfigurations for accommodating various next generation (e.g., 5G)communication requirements, such as Enhanced Mobile Broadband (eMBB),Massive Machine Type Communication (mMTC), Ultra-Reliable andLow-Latency Communication (URLLC), while fulfilling high reliability,high data rate and low latency requirements. The OrthogonalFrequency-Division Multiplexing (OFDM) technology as agreed in 3GPP mayserve as a baseline for NR waveform. The scalable OFDM numerology, suchas the adaptive sub-carrier spacing, the channel bandwidth, and theCyclic Prefix (CP) may also be used. Additionally, two coding schemesare considered for NR: (1) Low-Density Parity-Check (LDPC) code and (2)Polar Code. The coding scheme adaption may be configured based on thechannel conditions and/or the service applications.

Moreover, it is also considered that in a transmission time interval TXof a single NR frame, a downlink (DL) transmission data, a guard period,and an uplink (UL) transmission data should at least be included, wherethe respective portions of the DL transmission data, the guard period,the UL transmission data should also be configurable, for example, basedon the network dynamics of NR. In addition, sidelink resources may alsobe provided in an NR frame to support ProSe services or V2X services.

In addition, the terms “system” and “network” herein may be usedinterchangeably. The term “and/or” herein is only an associationrelationship for describing associated objects, and represents thatthree relationships may exist. For example, A and/or B may indicatethat: A exists alone, A and B exist at the same time, or B exists alone.In addition, the character “I” herein generally represents that theformer and latter associated objects are in an “or” relationship.

Because multi-beam operation may be supported in NR, an RA procedure inNR may be different from an RA procedure in Long Term Evolution (LTE).For example, before an RA is initiated, a base station (e.g., gNB) mayprovide to a UE, through system information, association informationbetween synchronization signal blocks (SSBs) and one or more RandomAccess Channel (RACH) resources. The base station may also provide, tothe UE, a reference signal received power (RSRP) threshold for SSBselection. After the RA is initiated, during the step of RA resourceselection, the UE may perform DL reference signal (e.g., SSB, or ChannelState Information Reference Signal (CSI-RS)) measurement for beamselection.

In NR, the RA procedure may be triggered by one or more of the followingevents, including:

-   -   initial access from a radio resource control (RRC) idle state        (RRC_IDLE);    -   RRC Connection Re-establishment procedure;    -   Handover (HO);    -   DL or UL data arrival during RRC connected state (RRC_CONNECTED)        when UL synchronization status is “non-synchronized”:    -   transition from RRC_INACTIVE;    -   establishing time alignment at Secondary Cell (SCell) addition;    -   request for other system information; and    -   beam failure recovery (BFR).

Based on whether an RA preamble transmitted by the UE has a possibilityof colliding with another UE's transmitted preamble or not, there may betwo types of RA: contention-based RA (CBRA) and contention-free RA(CFRA). A normal DLIUL transmission may take place after completion ofan RA procedure.

FIG. 1 is a diagram 100 illustrating an example CBRA procedure,according to an example implementation of the present application. ACBRA procedure may also be referred to as a 4-step Random Access Channel(RACH) procedure. In action 131, UE 110 transmits a Message 1 (Msg1) tobase station 120. The Msg1 may include a Random Access (RA) preambletransmitted on a Physical Random Access Channel (PRACH). In action 132,base station 120 transmits a message 2 (Msg2), which may include aRandom Access Response (RAR), to UE 110. The Msg2 may carry resourceallocation information, such as a UL grant, for a message 3 (Msg3)transmission. After UE 110 successfully decodes the RAR, in action 133,UE 110 sends the Msg3 on the granted resource to base station 120. TheMsg3 may include an RRC message, such as an RRC connection requestmessage. The Msg3 may be a MAC PDU carrying data that is received froman upper layer on a Common Control Channel (CCCH). During the RAprocedure, the Msg3 may be stored in a Msg3 buffer to prevent loss ofthe data received from the upper layer on the CCCH. In action 134, basestation 120 sends a message 4 (Msg4) to UE 110. The Msg4 may include acontention resolution MAC Control Element (CE).

FIG. 2 is a diagram 200 illustrating an example CFRA procedure,according to an example implementation of the present application. ACFRA procedure may also be referred to as a 2-step RACH procedure. Inaction 230, base station 220 assigns a preamble to UE 210. In action231, UE 210 transmits a Msg1 to base station 220. In action 232, basestation 220 transmits a Msg2, which may include an RAR, to UE 210.

In NR, before each preamble transmission or retransmission (e.g.,including the first preamble transmission and the preambleretransmission after each random back off) within an RA procedure, a UEmay perform an RA resource selection. During the RA resource selection,there may be two types of RA resources: a CBRA resource (e.g., therandom access preamble is selected by a MAC entity from one or morecontention-based random access preambles) and a CFRA resource (e.g., therandom access preamble is not selected by the MAC entity from one ormore contention-based random access preambles). It should be noted thatthe CFRA resource may not be necessarily configured to the UE by a basestation (e.g., a gNB). If the CFRA resource is configured by the basestation, the UE may prioritize the CFRA resource. In one implementation,the UE may select the CBRA resource only when the SSB (or CSI-RS)measurement associated with the CFRA resource does not satisfy an RSRPthreshold. In one implementation, the UE may select either the CBRAresource or the CFRA resource when both the SSB (or CSI-RS) measurementsassociated with the CBRA resource and the CFRA resource fail to satisfythe RSRP threshold.

In one implementation, if the RA procedure is initiated for BFR, a UEmay not select the CFRA resource if a beam failure recovery timer (e.g.,parameter beamFailureRecoveryTimer) is configured but is not running.The UE may be configured, by the base station through the RRC layer,with BWP specific BFR configuration (e.g., BeamFailureRecoveryConfiginformation element (IE)). Each BFR configuration may include a set ofRA parameters, which may be related to an RA procedure triggered by BFR.The set of RA parameters configured in the BFR configuration mayinclude:

-   -   rsrp-ThresholdSSB (e.g., an RSRP threshold for the selection of        the SSB);    -   rsrp-ThresholdCSI-RS (e.g., an RSRP threshold for the selection        of CSI-RS);    -   powerRampingStep (e.g., the power-ramping factor);    -   powerRampingStepHighPriority (e.g., the power-ramping factor in        case of prioritized RA procedure);    -   preambleReceivedTargetPower (e.g., initial RA Preamble power);    -   preambleTransMax (e.g., the maximum number of RA Preamble        transmission):    -   scalingFactorBI (e.g., a scaling factor for prioritized RA        procedure);    -   ssb-perRACH-Occasion (e.g., the number of SSBs mapped to each        PRACH occasion);    -   ra-ResponseWindow (e.g., the time window to monitor RA        response(s));    -   prach-ConfigurationIndex (e.g., the available set of PRACH        occasions for the transmission of the RA Preamble);    -   ra-ssb-OccasionMaskIndex (e.g., PRACH occasion(s) associated        with an SSB in which the MAC entity may transmit an RA        Preamble); and    -   ra-OccasionList (e.g., PRACH occasion(s) associated with a        CSI-RS in which the MAC entity may transmit an RA Preamble).

It should be noted that these RA parameters configured by a base stationmay be used in not only an RA triggered by BFR but also an RA triggeredby other events. In one implementation, a UE may be configured withmultiple configurations (e.g., values) of these RA parameters, with eachconfiguration corresponding to a different RA purpose. For example, RAinitiated for different purposes may be configured with differentconfigurations. In one implementation, the UE may be configured with aconfiguration for BFR and another configuration for initial access.Based on the purpose of an RA procedure, the UE may choose acorresponding configuration of these RA parameters.

In NR, a serving cell may be configured with one or more BWPs. In oneimplementation, a UE may activate one UL BWP and one DL BWPsimultaneously for each configured serving cell, and the UE may switchan active BWP. The BWP switching for a serving cell may be used toactivate an inactive BWP and deactivate an active BWP simultaneously.The BWP switching may be controlled by a Physical Downlink ControlChannel (PDCCH) indicating a downlink assignment or an uplink grant, bya BWP inactivity timer (e.g., a parameter bwnp-InactivitvTimer), by RRCsignaling (e.g., (re-)configuration of BWP(s)), or by a MAC entity ofthe UE itself upon initiation of an RA procedure when the current activeUL BWP is not configured with Physical Random Access Channel (PRACH)occasions (in this case, the UE may switch the active UL BWP to the BWPindicated by a parameter initialUplinkBWP configured by an RRC layer ofthe base station). The parameter bwp-InactivityTimer may be configuredby the base station. The active BWP for the serving cell may beindicated by either RRC signaling or a PDCCH.

Case 1: RRC (Re-)Configuration for BWP Switching

In one implementation, upon reception of an RRC (re-)configuration forBWP switching for a serving cell while a RA procedure associated withthat serving cell is ongoing in a MAC entity, the MAC entity may stopthe ongoing RA procedure and initiate another RA procedure afterperforming the BWP switching. In the following description, the ongoingRA before the BWP switching may be referred to as “the stopped RA”, andthe RA initiated by the MAC entity after the BWP switching may bereferred to as “the newly initiated RA”. In one implementation, the BWPswitching triggered by RRC signaling may only occur in the UL BWP, whichmeans the DL BWP may not be switched. Hence, the reference signalconfigured for beam failure detection (BFD) may also not change. In oneimplementation, BFD may be performed in the MAC entity. The MAC entitymay detect beam failure instance (BFI) indication received from thelower layers of the UE (e.g., a physical (PHY) layer of the UE) andcount the number of received BFI (e.g., parameter BFI_COUNTER). In oneimplementation, the MAC entity may initiate an RA procedure for BFR whenthe number of beam failure instances that have been received from thelower layers is larger than or equal to a threshold (e.g., parameterbeamFailureInstanceMaxCount).

In one implementation, if the ongoing RA before the BWP switching is forBFR, the RA procedure initiated by the MAC entity after the BWPswitching may also be for BFR. Hence, RA parameters in a BFRconfiguration may be applied by the MAC entity for the newly initiatedRA. In one implementation, the BFR configuration including the RAparameters may be configured by a base station per UL BWP, and the BFRconfiguration may only be applied by the MAC entity when the BFRprocedure is triggered (e.g., when the number of beam failure instancesreceived from the lower layers is larger than or equal to apredetermined threshold within a preconfigured time period). It shouldbe noted that the base station may not configure the BFR configurationincluding the RA parameters for all the UL BWPs.

In one implementation, there may be multiple RA parameters configuredfor the BFR RA. Instructions to ask the UE to apply the BFRconfiguration for each of the RA parameters may be addressed in at leastone of an RA initialization stage, a BWP operation procedure, and a BeamFailure Detection and Recovery procedure. In the following, severalimplementations are provided to address how a MAC entity applies a BFRconfiguration for each of the RA parameters for a newly initiated RA.

Case 1-1: In BWP Operation Procedure

Case 1-1-a: In one implementation, in a BWP operation procedure, a MACentity of a UE may only apply a specific part of the RA parameters inthe BFR configuration for the newly initiated RA. In one implementation,the specific part of RA parameters may include powerRampingStep,preambleReceivedTargetPower, and preambleTransMax. In oneimplementation, the specific part of RA parameters may includepowerRampingStepHighPriority, which may be a power ramping step appliedfor a prioritized RA procedure. In one implementation, the specific partof RA parameters may include scalingFactorBI, which may be a scalingfactor for a backoff indicator (BI). In one implementation, the specificpart of LRA parameters may include only part of the RA parameters in theBFR configuration (e.g., only part of following parameters:rsrp-ThresholdSSB, rsrp-ThresholdCSI-RS, powerRampingStep,powerRampingStepHighPriority, preamnbleReceivedTargetPower,preambleTransMax, scalingFactorBI, ssb-perRACH-Occasion, ra-ResponseWindow, prach-ConfigurationIndex, ra-ssb-OccasionMaskIndex, andra-OccasionList) or any other RA parameters introduced in the TechnicalStandard (TS) 38.321 and/or TS 38.331. The entire contents of TS 38.321and TS 38.331 are hereby incorporated by reference.

In one implementation, upon reception of an RRC (re-)configuration forBWP switching for a serving cell while an RA procedure associated withthat serving cell is ongoing in the MAC entity, the MAC entity may stopthe ongoing RA procedure and initiate an RA procedure after performingthe BWP switching. If the BWP switching is for a SpCell and a BFRconfiguration (e.g., BeamFailureRecoveryConfig) is configured for theactive UL BWP, the newly initiated RA may be for beam failure recoveryafter performing the BWP switching. The MAC entity may apply theparameters powerRampingStep, preambleReceivedTargetPower, andpreambleTransMax configured in BeamFailureRecoveryConfig for the newlyinitiated RA procedure. The SpCell may be a special cell, which mayrefer to a primary cell (PCell) in a master cell group or a primarysecondary cell (PSCell) in a secondary cell group.

Case 1-1-b: In one implementation, the specific part of RA parametersmay include all of the RA parameters rsrp-ThresholdSSB,rsrp-ThresholdCSI-RS, powerRampingStep, powerRampingStepHighPriority,preambleReceivedTargetPower, preambleTransMax, scalingFactorBI,ssb-perRACH-Occasion, ra-ResponseWindow, prach-ConfigurationIndex,ra-ssb-OccasionMaskIndex, and ra-OccasionList.

In one implementation, upon reception of an RRC (re-)configuration forBWP switching for a serving cell while an RA procedure associated withthat serving cell is ongoing in the MAC entity, the MAC entity may stopthe ongoing RA procedure and initiate an RA procedure after performingthe BWP switching. If the BWP switching is for SpCell and a BFRconfiguration (e.g., BeamFailureRecoveryConfig IE) is configured for theactive UL BWP, the MAC entity may initiate an RA procedure afterperforming the BWP switching and the newly initiated RA procedure may befor beam failure recovery. The MAC entity may apply the RAparameters/configurations configured in BeamFailureRecoveryConfig forthe newly initiated RA procedure.

Case 1-1-c: In one implementation, in the BWP operation procedure, theMAC entity may keep the purpose of the newly initiated RA the same asthe purpose of the stopped RA.

In one implementation, upon reception of an RRC (re-)configuration forBWP switching for a serving cell while an RA procedure associated withthat serving cell is ongoing in the MAC entity, the MAC entity may stopthe ongoing RA procedure and initiate an RA procedure after performingthe BWP switching. If the RA procedure before performing the BWPswitching (e.g., the stopped RA) is initiated for beam failure recovery,the RA procedure initiated after performing the BWP switching (e.g., thenewly initiated RA) may also be for beam failure recovery.

In one implementation, upon reception of an RRC (re-)configuration forBWP switching for a serving cell while an RA procedure associated withthat serving cell is ongoing in the MAC entity, the MAC entity may stopthe ongoing RA procedure and initiate an RA procedure after performingthe BWP switching. The purpose of the RA procedure after performing theBWP switching (e.g., the newly initiated RA) may be kept the same as thepurpose of the RA before the BWP switching (e.g., the stopped RA).

Case 1-1-d: In one implementation, if PRACH occasions are not configuredfor the active UL BWP, a MAC entity of a UE may switch the active UL BWPto an initial UL BWP (e.g., a BWP indicated by a parameterinitialUplinkBWP). The MAC entity may initiate an RA procedure after theBWP switching (e.g., the newly initiated RA). The newly initiated RA maybe performed on the initial UL BWP. The MAC entity may apply the BFRconfiguration (e.g., BeamFailureRecoveryConfig) of the initial UL BWPfor the newly initiated RA procedure. In one implementation, if the BFRconfiguration is not configured for the initial UL BWP, the newlyinitiated RA performed by the MAC entity may be just a CBRA, but thepurpose of the CBRA may still be BFR.

In one implementation, upon reception of an RRC (re-)configuration forBWP switching for a serving cell while an RA procedure associated withthat serving cell is ongoing in the MAC entity, the MAC entity may stopthe ongoing RA procedure and initiate an RA procedure after performingthe BWP switching. If the BWP switching is for SpCell and a BFRconfiguration (e.g., BeamFailureRecoveryConfig IE) is configured for theactive UL BWP, the LMAC entity may initiate an RA procedure afterperforming the BWP switching and the newly initiated RA procedure may befor beam failure recovery. The MAC entity may apply the parameterspowerRampingStep, preambleReceivedTargetPower, and preambleTransMaxconfigured in BeamFailureRecoveryConfig for the newly initiated RAprocedure. If PRACH occasions are not configured for the active UL BWP,the MAC entity may switch the active UL BWP to a BWP indicated by aparameter initialUplinkBWP. The newly initiated RA procedure after BWPswitching may be performed on the initialUplinkBWP, and the MAC entitymay apply the parameters powerRampingStep, preambleReceivedTargetPower,and preambleTransMax configured in BeamFailureRecoveryConfig of theinitialUplinkBWP. If the BFR configuration is not configured for theinitial UL BWP, the MAC entity may perform CBRA for the newly initiatedRA procedure.

In one implementation, upon reception of an RRC (re-)configuration forBWP switching for a serving cell while an RA procedure associated withthat serving cell is ongoing in the MAC entity, the MAC entity may stopthe ongoing RA procedure and initiate an RA procedure after performingthe BWP switching. If the BWP switching is for SpCell and a BFRconfiguration (e.g., BeamFailureRecoveryConfig IE) is configured for theactive UL BWP, the MAC entity may initiate an RA procedure afterperforming the BWP switching and the newly initiated RA procedure may befor beam failure recovery. The MAC entity may apply theparameters/configurations configured in BeamFailureRecoveryConfig forthe newly initiated RA procedure. If PRACH occasions are not configuredfor the active UL BWP, the MAC entity may switch the active UL BWP to aBWP indicated by a parameter initialUplinkBWP. The newly initiated RAprocedure after BWP switching may be performed on the initialUplinkBwP,and the MAC entity may apply the parameters/configurations configured inBeamFailureRecoveryConfig of the initialUplinkBWP.

Case 1-2: in BFD and BFR Procedure

A MAC entity of a UE may apply RA parameters in a BFR configuration forthe newly initiated RA procedure in BFD and BFR procedure. In oneimplementation, because a beam failure recovery timer (e.g., a parameterbeamFailureRecoveryTimer) may be configured per UL BWP, a MAC entity ofa UE may also apply the configuration for the beam failure recover timerconfigured for the new active UL BWP.

Case 1-2-a: In one implementation, in the BFD and BFR procedure, a MACentity of a UE may only apply a specific part of the RA parameters inthe BFR configuration for the newly initiated RA. In one implementation,the specific part of RA parameters may include powerRampingStep,preambleReceivedTargetPower, and preambleTransMax. In oneimplementation, the specific part of RA parameters may includepowerRampingStepHighPriority. In one implementation, the specific partof RA parameters may include scalingFactorBI.

In one implementation, a method performed by a MAC entity of a UE may beas described in the following Table 1:

TABLE 1 The MAC entity may: 1> if beam failure instance indication hasbeen received from lower layers: 2> start or restart thebeamFailureDetectionTimer; 2> increment BFI_COUNTER by 1; 2> ifBFI_COUNTER >= beamFailureInstanceMaxCount: 3> initiate a Random Accessprocedure on the SpCell. 1> if a Random Access procedure for the beamfailure recovery is initiated upon reception of RRC (re-)configurationfor BWP switching for the SpCell: 2> if BeamFailureRecoveryConfig isconfigured for the active UL BWP: 3> (re)start thebeamFailureRecoveryTimer, if configured; 3> apply the parameterspowerRampingStep, preambleReceivedTargetPower, and preambleTransMaxconfigured in BeamFailureRecoveryConfig for the Random Access procedure.

Case 1-2-b: In one implementation, the specific part of RA parametersmay include all of the RA parameters (e.g., rsrp-ThresholdSSB,rsrp-ThresholdCSI-RS, powerRampingStep, powerRampingStepHighPriority,preambleReceivedTargetPower, preambleTransMax, scalingFactorBI,ssb-perRACH-Occasion, ra-ResponseWindow, prach-ConfigurationIndex,ra-ssb-OccasionMaskIndex, and ra-OccasionList) or any other RAparameters introduced in the TS 38.321 and/or TS 38.331.

In one implementation, a method performed by a MAC entity of a UE may beas described in the following Table 2: Table 2

TABLE 2 The MAC entity may: 2> if beam failure instance indication hasbeen received from lower layers: 2> start or restart thebeamFailureDetectionTimer; 2> increment BFI_COUNTER by 1; 2> ifBFI_COUNTER >= beamFailureInstanceMaxCount: 3> initiate a Random Accessprocedure on the SpCell. 1> if a Random Access procedure for the beamfailure recovery is initiated upon reception of RRC (re-)configurationfor BWP switching for the SpCell: 2> if BeamFailureRecoveryConfig isconfigured for the active UL BWP: 3> (re)start thebeamFailureRecoveryTimer, if configured; 3> apply theparameters/configurations configured in BeamFailureRecoveryConfig forthe Random Access procedure.

Case 1-2-c: In one implementation, the specific part of RA parametersmay include only part of the RA parameters (e.g., rsrp-ThresholdSSB,rsrp-ThresholdCSI-RS, powerRampingStep, powerRamnpingStepHighPriority,preambleReceivedTargetPower, preambleTransMax, scalingFactorBI,ssb-perRACH-Occasion, ra-ResponseWindow, prach-ConfigurationIndex,ra-ssb-OccasionMaskIndex, and ra-OccasionList) or any other RAparameters introduced in the TS 38.321 and/or TS 38.331.

Case 1-3: In RA Procedure Initialization

Case 1-3-a: In one implementation, in an RA procedure initializationstage, a MAC entity of a UE may apply specific RA parameters in a BFRconfiguration according to the purpose of the initiated RA procedure.

In one implementation, an RRC layer may configure following parametersfor the RA procedure:

-   -   preambleReceivedTargetPower: initial Random Access Preamble        power. If the Random Access procedure is initiated for beam        failure recovery, the preambleReceivedTargetPower may refer to        preambleReceivedTargetPower in BeamFailureRecoveryConfig IE;    -   powerRampingStep: the power-ramping factor. If the Random Access        procedure is initiated for beam failure recovery, the        powerRampingStep may refer to powerRampingStep in        BeamFailureRecoveryConfig IE;    -   preambleTransMax: the maximum number of Random Access Preamble        transmission. If the Random Access procedure is initiated for        beam failure recovery, the preambleTransMax may refer to        preambleTransMax in BeamFailureRecoveryConfig IE.

It should be noted that the parameters listed above are just exemplaryrather than limiting. For example, the RRC layer may instead (oradditionally) configure other previously listed RA parameters, such aspowerRampingStepHighPriority, scalingFactorBI, or other RA parametersintroduced in the TS 38.321 and/or TS 38.331.

Case 1-3-b: In one implementation, in the RA procedure initializationstage, the MAC entity may keep the purpose of the newly initiated RA thesame as the purpose of the stopped RA.

Case 1-4: RRC Configuration

In one implementation, a UE may be asked to apply RA parameters in aconfiguration based on a purpose of triggering RA. In oneimplementation, when a base station configures a configuration for RAparameters, the configuration within an RRC message and IE mayexplicitly indicate that the configured RA parameters may be applied fora specific purpose of triggering RA. For example, withinRACH-ConfigGeneric, RACH-ConfigCommon, RA-Prioritization orBeamFailureRecoveryConfig IE, the RRC message may explicitly indicatethat the configuration may be applied for a specific purpose of RA(e.g., RA for BFR). Moreover, the RRC message may further explicitlyindicate that some specific configured RA parameters may be applied fora specific purpose of RA (e.g., RA for BFR). In one implementation, theRRC message may explicitly indicate that only some specific configuredRA parameters may be applied for a specific purpose of RA (e.g., RA forBFR).

Case 2: PDCCH for BWP Switching

In one implementation, if a MAC entity of a UE receives a PDCCH for BWPswitching for a serving cell while an RA procedure associated with thatserving cell is ongoing in the MAC entity, it may be up to UEimplementation regarding whether to switch BWP or ignore the PDCCH forBWP switching. In one implementation, when the UE receives a PDCCH forBWP switching that is addressed to a Cell-Radio Network TemporaryIdentifier (C-RNTI) for successful RA procedure completion, the UE mayperform BWP switching to a BWP indicated by the PDCCH. When the UEreceives a PDCCH for BWP switching other than successful contentionresolution, if the MAC entity of the UE decides to perform BWPswitching, the MAC entity may stop the ongoing RA procedure and initiatean RA procedure after performing the BWP switching. If the MAC decidesto ignore the PDCCH for BWP switching, the MAC entity may continue theongoing RA procedure on the serving cell. In one implementation, if theMAC entity decides to perform BWP switching, the behavior correspondingto the newly initiated RA procedure may be similar to that introduced invarious implementations in Case 1. The difference is that BWP switchingin Case 1 may be triggered by RRC configuration, and BWP switching inCase 2 may be triggered by PDCCH.

In one implementation, if the MAC entity decides to perform BWPswitching, the MAC entity may stop the ongoing RA procedure and initiatean RA procedure after performing the BWP switching. No matter whetherthe purpose of the stopped RA is for BFR or not, various implementationsof the MAC entity in Case 1 may be logically adopted for BWP switchingtriggered by PDCCH in Case 2.

Case 3: Other Implementations

In one implementation, upon reception of an RRC (re-)configuration forBWP switching for the SpCell while an RA procedure for beam failurerecovery is ongoing, a MAC entity of a UE may not initiate an RAprocedure after the BWP switching. In one implementation, upon receptionof an RRC (re-)configuration for BWP switching for the SpCell while anRA procedure for beam failure recovery is ongoing, the MAC entity maynot initiate an RA procedure after the BWP switching if the DL BWP hasbeen switched by the RRC (re-)configuration, and/or if theBFD/BFR/reference signal(s) (or signal set(s)) has beenchanged/updated/modified/reconfigured. In one implementation, the MACentity may set the beam failure instance counter (e.g., a parameterBFI_COUNTER) to 0, stop the beamFailureRecoverTimer, and/or consider theBFR procedure successfully completed. Various implementations for theMAC entity within this disclosure may be logically adopted to UL BWPswitching due to any kind of events (e.g., RRC signaling-basedtriggering, timer-based triggering or any downlink signaling).

FIG. 3 is a flowchart of an example method 300 performed by a MAC entityof a UE in an RA procedure, according to an example implementation ofthe present application. In action 302, the MAC entity may receive afirst beam failure recovery configuration of a first UL BWP (e.g.,BeamFailureRecoveryConfig #1). In action 304, the MAC entity may receivea second beam failure recovery configuration of a second UL BWP (e.g.,BeamFailureRecoveryConfig #2). Each of the beam failure recoveryconfigurations may be configured per UL BWP.

In action 306, the MAC entity may initiate a first RA procedure on thefirst UL BWP by applying at least one first RA parameter configured inthe first beam failure recovery configuration of the first UL BWP (e.g.,BeamFailureRecoveryConfig #1), when the number of beam failure instances(e.g., BFI_COUNTER) that have been received from the lower layers of theUE is larger than or equal to a threshold (e.g.,beamFailureInstanceMaxCount). The first RA procedure may be for beamfailure recovery. The at least one first RA parameter in the first beamfailure recovery configuration may include at least one of followingparameters: rsrp-ThresholdSSB, rsrp-ThresholdCSI-RS, powerRampingStep,powerRampingStepHighPriority preambleReceivedTargetPower, preambleTransMax, scalingFactorBI, ssb-perRACH-Occasion, ra-ResponseWindow,prach-ConfigurationIndex, m-ssb-OccasionMaskIndex, and ra-OccasionList.

In action 308, the MAC entity may switch an active UL BWP of the UE fromthe first UL BWP to a second UL BWP before completion of the first RAprocedure. The BWP switching in action 308 may be triggered by a PDCCHindication, a BWP inactivity timer, an RRC signaling, or by the MACentity itself when the first UL BWP is not configured with PRACHoccasions.

In one implementation, the MAC entity may receive an RRC message for BWPswitching before completion of the first RA procedure, and the MACentity may stop the first RA procedure. BWP switching triggered by RRCsignaling may be referred to the description of Case 1 above.

In action 310, the MAC entity may initiate a second RA procedure on thesecond UL BWP by applying at least one second RA parameter configured inthe second beam failure recovery configuration of the second UL BWP(e.g., BemnFailureRecoveryConfig #2), after switching the active UL BWPof the UE to the second UL BWP. In one implementation, the at least onesecond RA parameter applied by the MAC entity may includepowerRampingStep, preamnbleReceivedTargetPower, and preambleTransMax. Inone implementation, the at least one second RA parameter applied by theMAC entity may include powerRampingStepHighPriority. In oneimplementation, the at least one second RA parameter applied by the MACentity may include scalingFactorBL In one implementation, the at leastone second RA parameter applied by the MAC entity may include part orall of the RA parameters rsrp-ThresholdSSB, rsrp-ThresholdCSI-RS,powerRampingStep, powerRampingStepHighPriority,preambleReceivedTargetPower, preamnbleTransMax, scalingFactorBI,ssb-perRACH-Occasion, ra-ResponseWindow, prach-ConfigurationIndex,ra-ssb-OccasionMaskIndex, and ra-OccasionList. The RA parameters appliedfor the newly initiated RA procedure (e.g., the second RA procedure) maybe referred to the descriptions of Cases 1-1-a, 1-1-b, 1-2-a, 1-2-b,1-2-c, and 1-3-a, above.

In one implementation, the first UL BWP is not configured with PRACHoccasions, and the second UL BWP is an initial UL BWP of the UE (e.g., aBWP indicated by a parameter initialUplinkBWP). The related descriptionmay be found in Case 1-1-d.

FIG. 4A is a flowchart of another example method 400 performed by a MACentity of a UE in an RA procedure, according to an exampleimplementation of the present application. In action 402, the MAC entitymay initiate a first RA procedure on the first UL BWP, when the numberof beam failure instances (e.g., BFI_COUNTER) that have been receivedfrom the lower layers of the UE is larger than or equal to a threshold(e.g., beamFailureInstanceMaxCount). The first RA procedure may be forbeam failure recovery. The UE may not be configured with a beam failurerecovery configuration on the first UL BWP at this moment. In oneimplementation, the MAC entity may apply RA parameters configured inBWP-UplinkCommon IE, RACH-ConfigCommon IE, or RACH-ConfigGeneric IE, forthe first RA procedure.

In action 404, before completion of the first RA procedure, the MACentity of the UE may receive (e.g., from upper layers) a first beamrecovery configuration of the first UL BWP (e.g.,BeamFailureRecoveryConfig #1). The first beam recovery configuration maybe configured by a base station during the first RA procedure.

In action 406, the MAC entity of the UE may stop the first RA procedureand initiate a second RA procedure on the first UL BWP by applying atleast one RA parameter configured in the first beam failure recoveryconfiguration of the first UL BWP. The at least one RA parameter in thefirst beam failure recovery configuration may include part or all offollowing parameters: rsrp-ThresholdSSB, rsrp-ThresholdCSI-RS,powerRampingStep, powerRampingStepHighPriority,preamnbleReceivedTarge:Power, preambleTransMax, scalingFactorB,ssb-perRACH-Occasion, ra-ResponseWindow, prach-ConfigurationIndex,ra-ssb-OccasionMaskIndex, and ra-OccasionList.

FIG. 4B is a flowchart of another example method 400B performed by a MACentity of a UE in an RA procedure, according to an exampleimplementation of the present application. In action 410, the MAC entitymay receive a first beam failure recovery configuration of a first ULBWP (e.g., BeamFailureRecoveryConfig #1). In action 412, the MAC entitymay initiate a first RA procedure on the first UL BWP by applying atleast one first RA parameter configured in the first beam failurerecovery configuration of the first UL BWP (e.g.,BeamFailureRecoverConfig #1), when the number of beam failure instances(e.g., BFI_COUNTER) that have been received from lower layers is largerthan or equal to a threshold (e.g., beamFailureInstanceMaxCount). Thefirst RA procedure may be for beam failure recovery.

In action 414, the MAC entity may receive a second beam failure recoveryconfiguration of the first UL BWP (e.g., BeamFailureRecoveryConfig #2).For example, the beam failure recovery configuration of the first UL BWPis reconfigured by a base station. The second beam failure recoveryconfiguration may overwrite the first beam failure recoveryconfiguration. In action 416, the MAC entity may initiate a second RAprocedure on the first UL BWP by applying at least one second RAparameter configured in the second beam failure recovery configurationof the first UL BWP (e.g., BeamFailureRecoveryConfig #1). The second RAprocedure may be also for beam failure recovery.

FIG. 5 is a block diagram illustrating a node for wirelesscommunication, in accordance with various aspects of the presentapplication. As shown in FIG. 5, a node 500 may include a transceiver520, a processor 528, a memory 534, one or more presentation components538, and at least one antenna 536. The node 500 may also include an RFspectrum band module, a base station (BS) communications module, anetwork communications module, and a system communications managementmodule, Input/Output (I/O) ports, I/O components, and power supply (notexplicitly shown in FIG. 5). Each of these components may be incommunication with each other, directly or indirectly, over one or morebuses 540. In one implementation, the node 500 may be a UE or a basestation that performs various functions described herein, for example,with reference to FIGS. 1 through 4.

The transceiver 520 having a transmitter 522 (e.g.,transmitting/transmission circuitry) and a receiver 524 (e.g.,receiving/reception circuitry) may be configured to transmit and/orreceive time and/or frequency resource partitioning information. In someimplementations, the transceiver 520 may be configured to transmit indifferent types of subframes and slots including, but not limited to,usable, non-usable and flexibly usable subframes and slot formats. Thetransceiver 520 may be configured to receive data and control channels.

The node 500 may include a variety of computer-readable media.Computer-readable media may be any available media that may be accessedby the node 500 and include both volatile and non-volatile media,removable and non-removable media. By way of example, and notlimitation, computer-readable media may comprise computer storage mediaand communication media. Computer storage media includes both volatileand non-volatile, removable and non-removable media implemented in anymethod or technology for storage of information such ascomputer-readable instructions, data structures, program modules ordata.

Computer storage media includes RAM, ROM. EEPROM, flash memory or othermemory technology. CD-ROM, Digital Versatile Disks (DVD) or otheroptical disk storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices. Computer storage media doesnot comprise a propagated data signal. Communication media typicallyembodies computer-readable instructions, data structures, programmodules or other data in a modulated data signal such as a carrier waveor other transport mechanism and includes any information deliverymedia. The term “modulated data signal” means a signal that has one ormore of its characteristics set or changed in such a manner as to encodeinformation in the signal. By way of example, and not limitation,communication media includes wired media such as a wired network ordirect-wired connection, and wireless media such as acoustic, RF,infrared and other wireless media. Combinations of any of the aboveshould also be included within the scope of computer-readable media.

The memory 534 may include computer-storage media in the form ofvolatile and/or non-volatile memory. The memory 534 may be removable,non-removable, or a combination thereof. Example memory includessolid-state memory, hard drives, optical-disc drives, and etc. Asillustrated in FIG. 5, The memory 534 may store computer-readable,computer-executable instructions 532 (e.g., software codes) that areconfigured to, when executed, cause the processor 528 to perform variousfunctions described herein, for example, with reference to FIGS. 1through 4. Alternatively, the instructions 532 may not be directlyexecutable by the processor 528 but be configured to cause the node 500(e.g., when compiled and executed) to perform various functionsdescribed herein.

The processor 528 (e.g., having processing circuitry) may include anintelligent hardware device, e.g., a Central Processing Unit (CPU), amicrocontroller, an ASIC, and etc. The processor 528 may include memory.The processor 528 may process the data 530 and the instructions 532received from the memory 534, and information through the transceiver520, the base band communications module, and/or the networkcommunications module. The processor 528 may also process information tobe sent to the transceiver 520 for transmission through the antenna 536,to the network communications module for transmission to a core network.

One or more presentation components 538 presents data indications to aperson or other device. Examples of presentation components 538 mayinclude a display device, speaker, printing component, vibratingcomponent, etc.

From the above description, it is manifested that various techniques maybe used for implementing the concepts described in the presentapplication without departing from the scope of those concepts.Moreover, while the concepts have been described with specific referenceto certain implementations, a person of ordinary skill in the art mayrecognize that changes may be made in form and detail without departingfrom the scope of those concepts. As such, the described implementationsare to be considered in all respects as illustrative and notrestrictive. It should also be understood that the present applicationis not limited to the particular implementations described above, butmany rearrangements, modifications, and substitutions are possiblewithout departing from the scope of the present disclosure.

What is claimed is:
 1. A user equipment (UE) comprising: one or morenon-transitory computer-readable media having computer-executableinstructions embodied thereon; and at least one processor coupled to theone or more non-transitory computer-readable media, the at least oneprocessor is configured to execute the computer-executable instructionsto: receive, by a Medium Access Control (MAC) entity of the UE, a firstbeam failure recovery configuration of a first uplink (UL) bandwidthpart (BWP); receive, by the MAC entity of the UE, a second beam failurerecovery configuration of a second UL BWP; initiate, by the MAC entityof the UE, a first Random Access (RA) procedure on the first UL BWP fornotifying a base station of a beam failure occurrence in a serving cellby applying at least one first RA parameter configured in the first beamfailure recovery configuration of the first UL BWP when a number of beamfailure instances that have been received from lower layers of the UE islarger than or equal to a threshold; receive a Radio Resource Control(RRC) message that triggers BWP switching before completion of the firstRA procedure; switch, by the MAC entity of the UE, an active UL BWP ofthe UE from the first UL BWP to the second UL BWP upon receiving the RRCmessage and before completion of the first RA procedure; and initiate,by the MAC entity of the UE, a second RA procedure on the second UL BWPfor notifying the base station of the beam failure occurrence regardlessof a number of beam failure instances received after switching theactive UL BWP of the UE to the second UL BWP by applying at least onesecond RA parameter configured in the second beam failure recoveryconfiguration of the second UL BWP, after switching the active UL BWP ofthe UE to the second UL BWP.
 2. The UE of claim 1, wherein the at leastone second RA parameter comprises a power ramping step applied for aprioritized RA procedure.
 3. The UE of claim 1, wherein the at least onesecond RA parameter comprises a scaling factor for a backoff indicator(BI).
 4. The UE of claim 1, wherein the at least one processor isfurther configured to execute the computer-executable instructions to:stop the first RA procedure.
 5. The UE of claim 1, wherein the first ULBWP is not configured with Physical Random Access Channel (PRACH)occasions, and the second UL BWP is an initial UL BWP of the UE.
 6. Amethod for random access (RA) performed by a Medium Access Control (MAC)entity of a user equipment (UE), the method comprising: receiving afirst beam failure recovery configuration of a first uplink (UL)bandwidth part (BWP); receiving a second beam failure recoveryconfiguration of a second UL BWP; initiating a first Random Access (RA)procedure on the first UL BWP for notifying a base station of a beamfailure occurrence in a serving cell by applying at least one first RAparameter configured in the first beam failure recovery configuration ofthe first UL BWP when a number of beam failure instances that have beenreceived from lower layers of the UE is larger than or equal to athreshold; receiving a Radio Resource Control (RRC) message thattriggers BWP switching before completion of the first RA procedure;switching an active UL BWP of the UE from the first UL BWP to the secondUL BWP upon receiving the RRC message and before completion of the firstRA procedure; and initiating a second RA procedure on the second UL BWPfor notifying the base station of the beam failure occurrence regardlessof a number of beam failure instances received after switching theactive UL BWP of the UE to the second UL BWP by applying at least onesecond RA parameter configured in the second beam failure recoveryconfiguration of the second UL BWP, after switching the active UL BWP ofthe UE to the second UL BWP.
 7. The method of claim 6, wherein the atleast one second RA parameter comprises a power ramping step applied fora prioritized RA procedure.
 8. The method of claim 6, wherein the atleast one second RA parameter comprises a scaling factor for a backoffindicator (BI).
 9. The method of claim 6, further comprising: stoppingthe first RA procedure.
 10. The method of claim 6, wherein the first ULBWP is not configured with Physical Random Access Channel (PRACH)occasions, and the second UL BWP is an initial UL BWP of the UE.